Meanwhile, State Comptroller Micah Lindenstrauss is to decide next week whether to launch a formal investigation into the allegations.

The Channel 10 report included a list of dozens of trips allegedly taken by Mr Netanyahu and his wife Sarah - and in some cases also their two sons - to Europe and North America.

In addition, the channel published a private list of Jewish millionaires who allegedly could be "relied upon" to finance the Netanyahu family's holidays abroad. The channel claims the Netanyahus did not pay for any of their flights or the hotels and resorts where they were put up.

If the allegations against him are correct, Mr Netanyahu could be in breach of the Knesset's ethical code that forbids acceptance of gifts and sponsors who have business dealings in Israel, and he may be also investigated for bribery.

Sources close to the prime minister said that all the trips paid for by foreign donors were for lectures he gave defending Israel.

His office also said: "The descriptions are ridiculous. For example, the number of trips ascribed to Ms Netanyahu is wrong and the sequence of events, holidays, alleged sponsors and circumstances of each trip is totally divorced from reality."